Just some advice as you note in your profile that you're new. If you're thinking about doing exhaust work in the future, a sawzall and angle grinder are really a must have. Look around for used ones at garage sales, Craig's list, borrow a neighbor's etc. For me, other necessities are ratchets, wrenches, floor jack and car ramps too. Everything you will work on is almost always either under the car or requires taking the wheels off so find a few things to make life easier to start.

PB Blaster is my favorite too. Soak and let sit a few times. I've taken off exhaust manifold bolts/nuts, shock nuts, spring bolts etc off with PB and a good long breaker bar. Also, a great tool for nuts that won't come off is a nut extractor. Amazon sells the kind that tighten and bite into nut while you're turning them. Another great add to your tool box. You don't have to go crazy and get new tools. Lots of old tools from estate sales or guys not using them anymore turn up. Older wrenches are usually better quality than new anyway.

I learned a lot wrenching on my 87 Cherokee and had a lot of help and advice from this forum in particular. Best of luck.

 

thanks man! im not TOTALLY new to working on cars, i had a 77Camaro in 88 i used to tinker with. My most recent car (before the XJ) was an HHR i also tinkered with a bit, but i was married at the time and used my father in laws tools/stuff so i didnt buy much. But yea i have plans to buy a bunch of tools and floor jack, jack stands, ramps, saws-all etc etc. I have a pretty good range of ratchets, an angle grinder, Dremel, an assortment of open end wrenches etc etc. But i am full on planning on expanding the tool box now that i have something to work on again! thanks for the tips about garage sales etc didn't think of that! Nut extractor sounds like a good thing to have in the tool box as well!

haha yea PB blaster is some good stuff. I used it on my vintage sewing machines, and my BMX bikes in recent years.

It's going to finally stop raining by tomorrow and all next week looks nice out so gonna see what i can do to get this off. Then i have to do the EVAP line. Will probably replace the rotten line with a rubber fuel line.

Thanks again for the tips/advice!

 

My mate owns an exhaust shop 40yrs, they just heat any rusty nut with oxy and an impact driver

Over the last 10 years, after working on old vehicles for nearly 50yrs, I have refined my stuck fastener removal techniques, and a simple gas can butane torch will heat up most small fasteners enough

they dont need to be red hot, a butane torch will make them glow, the metal expands

the only real obstacle is excessive hard corrosion on the exposed threads

I have cut my broken fastener ratio to 0% for the last few years, working on some very old stuff

if you are able to get a spanner or socket on them, and use the torch to blast them, cool with PB (take precautions against fire), work back & forth

very good for general Jeep work, may be quicker to cut if they are very easily accesible, but succesful removal using above technique will improve your skills and confidence

I have not broken a single fastener on my XJ, despite rebuilding suspension, diffs, brakes, transmission, electricals etc etc

 

But in OP's case that is a very big "if" - the whole problem is there's not enough of the nuts left to get anything on them. Of course there are special tools for that very problem, I have a set but cannot remember what they're called; difficulty might be that an exhaust is not solid enough to hammer the device onto the remains of the nut.

 

My first try is Metwrinch tools if the fastener is skanky

These are pro quality tools I have had for about 40 years, they do Imperial, Metric and Whitworth with one tool (so good for XJs) and designed to get rounded fasteners

I have a set of alligator spanners that go next, or as you say, pound a socket over it

If cutting is best, I cut. It is often not an option, and must come out. You do not want breakage as they have to be drilled and extracted, which is time consuming and nasty

Patience is excellent. Most professional mechanics I know absolutely hate working on vehicles where every fastener is rusted or the vehicle poorly maintained and oil soaked

 

I've got some of those sockets, bit of a novelty back when the UK motor manufacturers started going metric, I thought they were just to reduce the number of sockets you needed, I don't remember them being particularly good quality, or even a good fit because they were always a compromise. Hardly used, I doubt many others have any or that you can still get them.

I didn't mean just any old (slightly smaller) socket but something that is spirally knurled, with sharp edges, that will cut into however little is left of the nut; mine are driven by a slightly oversized hex although there are socket that will work in the same way: probably better quality, certainly more expensive.

 

Yes, you can still order the Metwrinch, they are made in Germany.

I only use them for damaged fasteners, never for regular work, they are beyond annoying due to sloppy fit, as you say, but they act on flats, not corners

There are a few different specialised socket sets that do similar, as you say, I have considered to buy some, but havent needed them

 

Most 6-point sockets act on the flats now (if you look carefully at the profile of the hex, you can understand why they're a bit dearer.)

Found a piccie of what a was trying so badly to describe - but as the source was my Evilbay purchase record, showing it here is just too difficult (at least, for me). However, the one job I bought them for
made the purchase worthwhile - highly recommended